Drafting instrument.



S. RASHKOVSKY.

DRAFTING INSTRUMENT.

APPLICATION man MAR. 4. I9I8.

Patented Dec. 3;1918.

mvewaar:

curved :line, either circularly, elliptically, parabolically or hyperboli cally or, in other. Words, an :instrument vcapable of. adjustment.

"samuntnasi xovsxy, orsir, LOUIS, rmssoum.

- pnarmnu msrmu vmnr- Toallwhamit mayronaemr:

; Be itknown' that l, SAMUEnRAsrr ovsrrx a citizen of the -UnitedStates, residing n the city of St. Louis and State :io'f IMissouri,

have invented a new and useful lmproiize j ment .in Drafting Instruments, Gf WlI-ICh the followingis aspecification. c v c e This invention relates tof-draftingkinstrum'ems, andzmore particularly to .an instrument ffor describing or generating a regular and usexsimila r to ordinary compasses, to describe true 01116188 of ValRlOllSdlfilnGllGBS;

" and conic sections, such .astellipses of different major and .minor diameters {and as .a generatorof a parabola orLhyperbola.

, Generally stated, theiinuention residesinan instrument revoluble, either cylindrically or .conically, about a ffixed axis, and comgenerating or scribing Ibar -.or' 1egbeing..ca-

prising an axis-bar or leg :and a generating orscribing bar or .leg havlng .a PlVQtQllY and extensibly ad ustable connect1on,.sa1d

pable of movementlongitudinally and ro- "tatabiy Withrespecttorits a'Xis,.or setinifixed relation to .said axis=bar, at will, and tiltv able supporting member or device in which.

said axis bar .or leg may Ibe-Imounted with longitudinal andrrotativemovement with respect .to its axis.

- mentinldescribingamellipse; v

The invention has for-its principal objects to produce, in an instrument of, the said 5 character, a simple and teflicientnstruct-ure which is readily adjusted :for lthe-purposes intended .and-fis easily manipulated. iQthl, objects and vadvantages .to v be attained hereinafter more fully appear;

and forming apart ofthisfspecification e ,1 Figure 1 lisa view,in side\elevation, villusc trating; an: adjustment; and use ,oiz-zthe i'nstruinstrumentfisused as compasses or as an allipsograph or a" generator :of ia parabola or hyp'erbolm-as "will lbeslater vherein set;

Fig. S1,;

, 1 :In vthe accompanying drawings, Iillustrating .a practical .-adaptation,ofwthezinvention,

1 P 'I fl' nfi t nt. TatentedDe'e; 3,1918; ,musin gamma. 191a. seriamamm i as compasses in describing a circle; in E1, g. s plan VlBW of the ,mstrument :as ShoWnin F g. 3,;

Fig-.15 s .a detail View of an linking device or pan :to be used interchangeably Withithe pencilholdershown in'Figs. L1 andB; 3

Referring now to the drawings, therllin-c strument, [as therein shown, comprises {an axis-bar or leg 1 which is provided With-an ordinary needle-point 2 at \one :end, and has its opposite end portion knurled, as rat (3 or otherwisetsuitablyflformed or provided CDl'IVBIllBIltLIHQJHiPHIatIHgE'mHIDS.

a split. sleeve see Fig, ),,said sleeve lhaxzing ears or lugs I5, '6, which are lapertured, the

one, 6 beingscrewihreaded, so .as to receive v a c'lamp'ing screw 7.

, IThe clamping screw 17 is inserted through or lug 11 :Which is .apertured and screwthreaded to accommodate a clamping screw 12 Q( see Fig; 4),, said -clamping :screw 12Lbeing inserted "through the .slot in ,the zbar in a manner similareto the first-mentioned ngangadj ustment 'and'iuse'of the instrument As shown, this rOn the bar .'1 is' a member-4 which JUs'table lengthwise lthereof in some suitable, manner. 'As shown,..this;member4comprises screw 7. This sleeve 9 islalso sp'liti'andprm" vided With -GZLI'S or lugs 13, 14, Whichiare apertured, therone, 14, being SClTGVV-ihlffifidd, for. ,the-Lreception of a (ilampingscrew 415,

on the said baru10, nor l'loosened [so :that the bar may slide freely ltherethrough, ,as the, case may be, depending as to whether-the I .95

'90 whereby the sleeve may bereither tightened.

so as to'prevent the shank rfrom turning in In this use, the axis-bar 1 and scribing bar desirable construction and arrangement, but they are conventionally shown, for practicalpurposes, as having their shanks bifurcated, as at 20, so as to fit the socket 16 snugly with spring effect; and said shanks are further provided with splines or keys 21, which fit in a slot provided therefor in the bar 10,

the socket, v I The application of the instrumentas compasseswill be first described and the same is illustrated in F igs. 3 and 4' of the drawings.

10 maybe set either in parallel relation, as shown, orinangular relation, as desired; and, in such relation, they are rigidly con nected, through the bar 8 and themembers 4 and 9, by tightening the clamping screws 7, 12'and 15. i I

Obviously, by swinging the instrument around on the axis-bar or legl, thelscribing bar or leg 10 describes' or generates a circle on aplanefsurface, just the same as'i f ordinary compasses were used.

3 In its use as compasses, the instrument is capable of extensive adjustment, in that the" members aand 9 are shiftable on the bars 1 and 10, and the connecting bar.8 is also adjustable, both lengthwise and pivotally, on said members 4: and 9. Hence, the range'of adjustment is from very'small circles, such as are described by the ordinary two-legged compasses, to exceedingly large circles whlch ordinarily require the use of beam compasses or the like. v .i

The'use of the instrument as an ellipsog raph or in generating a parabola or hyperbola will now be described. In this use, the instrument is revolved while the aXis-bar 1 is held with its axis fixed in an inclined or tilted relation to the vplane of the section or surface to be inscribed or marked, and the clamping'screw 15 is loosened so that the generating or scribing bar 10 will slide easily through the sleeve 9. 1

The axis-bar 1 and the generating bar 10 maybe set parallel with each other or in angular relation so as to describe either a cylinder or a cone in revolution.

If the two bars 1 and '10 are parallel, or if at .an angle to each other, and the angle is less thanthe angle at which the bar 1 isv set with r c to t 1 p ft Section v Ql'L SUIfZtQG to be inscribed or marked, the line generated will be elliptical and continua; o'us, as the marking or scribing point of the bar 10 never leaves the surface or plane, it being understood, ofcourse, that the bar 10 is free to slide through the sleeve 9. Hence the outline will be an ellipse and a section 0 a cylinder or a cone, as. the case may be. If the angle of the-two bars 1 and 10 is equal to the angle of the bar 1 with respect j to. the plane ofsection or surface to be in scribed or marked,tlie" generating or SCIlb-' metrically opposite pointsand describe a parabola as long as it remains in. contact with the surface. ,Likewise, if the angle "is 'greaterfth e instruinent will describe a hy perbola. j d T To holdthe axis-bar 1 in tiltedor angular relationxto the'surface toibe'inscribed, it is ing bar 10; will leave the surface at dia pl dr a bly. d il h u l n y mo bl in a supporting tubeor-sleeve22 whichhas it a pivotal adjustmenton a ba 23; As shown, he basef23 omprises .a flat,

trifoliate plate having a pairof upstanding, I

parallel ears-or gs*'2 &-,12 t' thereon, between: whlch an ear or lug 26 11 the sleeve 22 extends. The respectiveear'sior lugs 24-, 25' and 26, have axiallyalined apertures, and the ear or lu 25 has a boss or protuberance 27 surroun ing its aperture which is screw threaded, so as to accommodate a clamping screw 28, whereby the sleeve 22 maybe fastened in whatever tilted position it may be setwithrespec-t to the base 23. The base may also be provided on its under side with" two or more prongs'or teeth 29 to be' pressed into a drawing-board,ithrough 'the'paper or other material thereonto be inscribed, or into any surface on which" the instrument may be used; and itis also preferable tofpro vide a medialrecess orire'e'ntrantportionx30 in the" base-plate to makeclearance for the needle-point 2 of-the axis-bar 1 (see Fig. 2) 'lhe base-plate may be further provided withthea medial pointed projection 31 or other suitable indication or mark-to coincide with the axial line of the ellipse or section to be described whenthe needle-point 2. is made to touch the same'line, so 'asto fa cilltate the proper positioning of'the instrument. A

To use the instrument in the easiest and simplest way, in describing an ellipse, the

axis bar 1 and the generating bar 10 are, first adjusted inspacedparallel relation accordingto' the minor diameter or axis of the ellipse; that is, so that the perpendicular dis-" tance between the needle-point -2..and scrib ing or marking point of the barjlll' is equal to one-half the diameter. Then the axis-bar 1. in the sleeve, 22.). with the generating bar 10 in line therewith, tilted ilntil the dis-l tance between the needle' point 2 and scrib ing or marking'point of the bar-.10 is equal,

to one-halfthe majordiameterof the ellipse along the plane of the section orsurface to be inscrib'ed, said bar 1 being freely slid able'in the sleeve -22 and the-bar 10 likewise slidable in1tl1esleeve '9,-- as hereinbefore pointed out; a In this instance the needlepoint i 2 coincides with L the intersection "of the two axes or center of the ellipse and the The instrument being positioned alon g thje major axis of the ellipse, as shown in Figs. 1

a. I and 2 of the drawings, the outline mayv be easily generated by steadying the sleeve and its base 23 with one hand, and, with the other-hand manipulating the generating or scribing bar 10 and exercising care to keep the marking point of the bar '10 in contact with the surface being inscribed while rotating the instrument about the axis of the inclined bar 1. I

In the same'way it is possible to generate an ellipse with the two bars or legs 1 and 10 in angular relation to each other. In such an instance the instrument will describe, in revolution, either a cone with apex upward or aninverted cone, depending whether they diverge or converge toward the surface be ing inscribed. That is, if the angle between the two bars is less than the angle between the bar 1 and the surface being inscribed when divergent. If convergent, the relative angularity of the two bars with respect to the angularity of the bar 1 and surface being inscribed, matters not, as the scribing point can be made to touch said surface throughout the entirerevolution of the instrument. Hence, an ellipse will be described. 7

If the angle between the two bars 1 and 10 is equal to the angle between the bar 1 and the surface being inscribed, the outline described will be aparabola, as the scribing point will leave the surface at a point on either side of the bar 1. Likewise, if the angle between the two bars 1 and 10 is greater than the angle between the bar land the surface being inscribed, the scribing point'will leave thesurface, butthe line de scribed willbe a hyperbola. a Toadjust the instrument in describing a .conic' section, a, more complex mathematical calculation is required than when setting it I fora cylindrical section, but it is within the possibilities of the invention; and the ad-I 'justment'may be facilitated by providingsuitable graduations or indications on the two bars land 10 and the connecting bar 8, witlrcorrelated markings. on the'sleeves 1 and 9. The details of such arrangements are not a part ofthe present application, and, therefore, are not herein set forth with particularity.

Obviously, the device admits of considerable. modification :andv changes without: departing from the spirit of the'invention as definedxbytheappended' claims; The invention, "therefore, is not limited tov the exact construction and: arrangement shown;

whatlslc'laimedisz a "-"1..I n an instrument-of the character described, an axis leg, a supporting member adjustable longitudinally on said leg,- a sec..- ond supporting member, a connecting bar having a longit'udinally' and pivotally-adi- 'ustable engagement with said supporting -members, a scribing leg slidable longitudinally and rotatably on said second men? tioned supporting member, and means for fastening said scribing leg to its supporting member at will.

2. In an instrument of thecharacter described, an axis leg,a supporting member adjustable longitudinally on said leg, a second supporting member, a connecting bar having a longitudinally and pivotally adjustable engagement with said supporting members,'a scribing leg slidablelongitudinally and rotatably. on said second mentioned supporting member, means for fastening said scribing leg to its supporting mem-. her at will, and a separable supporting and positioning device having a tiltable member through which the resting end portion of said axis leg extends and is capable of Ion gitudinal and rotative movement therein.

'3. A unitary scribing device comprising an axis leg having an axially pointed resting end, a generating leg having a scribing point,

a sleeve slidable on said axis leg, a sleeve slidable on said generating leg, a connecting bar having a longitudinally and pivotally adjustable engagement with said sleeves, means for fastening said axis leg, sleeves, and connecting bar in relative adjusted position, and means for fastening'said generat ing legs to its sleeve at will, and a separate unitary supporting and positioning device comprising a base, and 'a sleeve adjustable tiltably thereon and through which the resting end portion of said axis leg is capableof longitudinal androtati've movement and is supported with its resting point 'on the surface to be inscribed. 1

4. In an instrument of the character described, an axis-bar or leg, a generating bar or leg, a supporting member adjustable longitudinally on said axis-bar or leg, a supporting member slidable rotatively and longitudinally on said generating bar or leg, a

connectingbar having a longitudinally and pivotally adjustable engagement with said two mentioned supporting members, and

'means for fastening said axis bar or leg,

generating bar or leg, connecting bar. and supporting members either in absolutely fixed relation, or said axis-bar or leg and said connecting bar in fixed relation to the respective supporting members only while .Oepiesef this patent niaf'be ofpteinedfoi:

said generating bar or leg is permittedrrotative andlongitudinalmovement en said 'secondementioned supporting member, a

5. In an instrument of he character d escribed, an axis-bar orzleg, a. generating bar or leg, a longitudinally slotted connecting bar, a split sleeve on-said. exis-barvor leg, a clamping-screw for fastenlng SfildJSlEBVQjO said axis-bar or leg and said connecting bar,

a split: sleeve on said, generating bar or leg, a: clamping screw for fastening said sleeve to saideonnecti-ng bar, and a clamping-screw 

